Hioki PQ3100 - Page 187

181
Calculation Formula
10. Voltage negative-phase unbalance factor (Uunb), Voltage zero-phase unbalance factor (Uunb0),
Current negative-phase unbalance factor (Iunb), Current zero-phase unbalance factor (Iunb0)
Wiring
Item
Single phase
2-wire
1P2W
Single phase
3-wire
1P3W
3-phase 3-wire
3P3W2M
3-phase 3-wire
3P3W3M
3-phase 4-wire
3P4W
Uunb[%]
U
unb
=
100×
pos
neg
U
U
Uunb0[%]
U
unb0
=
100×
pos
zero
U
U
Iunb[%]
I
unb
=
100×
pos
neg
I
I
Iunb0[%]
I
unb0
=
100×
pos
zero
I
I
3-phase 3-wire
3P3W2M
3-phase 3-wire
3P3W3M
3-phase 4-wire
3P4W
Uzero
Upos
Uneg
( ) ( ) ( )( ) ( ) ( ) ( )( )
2
321
2
321
3sin2sinsin3cos2coscos
3
1
seqUseqUUseqUseqUU +•++•+•++•++•+•
γβαγβα
• The fundamental RMS voltage (phase voltage) from the results of harmonic calculations is used.
•
α
: Phase angle of
U
1
,
β
: Phase angle of
U
2
,
γ
: Phase angle of
U
3
• Use 3P3W2M after vector calculations in phase voltage as it is detected by line voltage.
Izero
Ipos
Ineg
( ) ( ) ( )( ) ( ) ( ) ( )( )
2
321
2
321
3sin2s insin3cos2coscos
3
1
seqIseqIIseqIseqII +•++•+•++•++•+•
γβαγβα
• The fundamental RMS current (phase voltage) from the results of harmonic calculations is used.
•
α
: Phase angle of
I
1
,
β
: Phase angle of
I
2
,
γ
: Phase angle of
I
3
• For 3P3W2M, the calculations are performed with
I
2
and
I
3
replaced with each other.
Seq2 Seq3
Uzero
,
Izero
0° 0°
Upos
,
Ipos
120° 240°
Uneg
,
Ineg
240° 120°
14
Specications